Mistake
by cergia
Summary: The young daughter of Sally and Paul Blofis resents her older brother, Perseus. When she makes a promise to her parents stating that she will no longer be rude to Percy, she decides to "welcome him to the family" by pulling a prank on him. What happens when this small prank triggers his PTSD?
1. Chapter 1

Being the youngest child had plentiful perks; those including obviously being the favorite child, consistently getting what you wanted, and overall having a wonderful life, especially if you were the offspring of Sally and Paul Blofis. It was a great privilege in Estelle's eyes, the way her life had been shaped and crafted. Yet; every perk and privilege has its downside, and to Estelle Blofis, this was the absolute worst downside of them all.

Garnering all of the attention for being the youngest was something you got used to- and when it was taken away, it was as if an angry spark had been lit inside of you, slowly growing into a large, burning fire of rage. This was something Estelle certainly experienced, but only with one person; her older brother, Perseus Jackson.

It soon became clear to Estelle that most younger children were the shining, bright stars of the family, yet she was not that, for that title belonged to Percy. This piece of knowledge angered the nine-year-old to the core, and jealously consumed her body each time he would return from his prestigious school, which was when all of the looks that had been pushed her way would soon disappear and flock over to that of her brother.

However, the moment he took his leave, it was as if a sense of happiness filled Estelle's vision. The incoming thoughts of having her parents back was exciting, particularly having their full attention. But it seemed as if her happiness was short lived, for the moment she returned home from school on September 13th, an exact month since Percy had discarded from their quaint home, there he was, a sullen look etched onto his tan face as her father comforted him.

"Dad?" She questioned, eyeing her brother angrily. She couldn't understand or wrap her head around what was currently happening; once her brother left, he didn't return until months later- but only a month since his departure was _absolutely wrong_!

Glancing behind him, Paul gave Estelle a look as if to say, " _not now_ ". His blue eyes matched her own in their fierce stare off, before Percy suddenly stood up, rubbing the back of his neck nervously.

"Sorry, Estelle." He apologized, a toothy grin appearing onto his face. Estelle grew angrier at his lopsided smile- but the moment she glanced into his apologetic sea-green eyes, she felt herself grow guilty. To avoid anything sentimental, she stated towards the ground, furiously grinding her foot against the dark rug beneath her.

"You don't have to be sorry, Perce." Her father's voice sounded exasperated and angry all at once, and Estelle knew exactly which one was directed towards her. "She needs to get used to this. After all, you live here, too."

"Since _when_?" Estelle muttered, a small scoff escaping her slightly parted lips. Lifting her head, she came face-to-face enraged eyes of her father. Fear coursed through her veins as she realized the mistake in her action.

"I will not tolerate this type of attitude towards your brother, Estelle." Paul firmly stated, glancing towards her room. "Go to your bedroom."

"Paul, it's alright." Percy attempted to diffuse the situation, awkwardly shuffling his foot. "She doesn't know me very well, it's understandable she's cold."

"I know you very well!" Estelle yelled, slamming her foot against the floor in frustration. "You only come here to steal my mom and dad away from me!"

"Estelle! Cut it out!" Paul matched her tone and anger perfectly as he marched over towards her, grasping her firmly by the arm, tugging her towards her bedroom.

"You know it's true!" She cried out, tears dripping down her pale cheeks. Before she could even utter another word, Estelle had been pushed into her bedroom with the door slammed behind her. Even with her favorite color surrounding her in heaps, Estelle could not find an ounce of happiness within her small bones.

Hours upon hours passed, and Estelle still sat in the same position against her brightly colored bed, her brown hair sticking to her cheeks in strands. She could faintly hear her mother and father speaking in hushed tones, but the disgusting voice of her brother was nowhere to be heard. A small flicker of joy scurried across her features, until she heard the deep snore sound in the room next to her own, and she realized that he was not leaving.

Grumbling, Estelle stood, brushing off the lint of her white colored dress. As she exited her dark room, the hushed whispers of her parents halted. Turning, she met the stares of both her mother and father, who motioned her to take a seat in front of them. Dread rushed through her, and her heart slammed against her chest rapidly as she thought of all of the trouble she was going to experience.

"Estelle," her mother began as she took a seat on the blue couch inhabiting their living room. "How could you even utter words as such?"

"Because it's true, mom!" She exclaimed, her blue eyes widening. Estelle thought that out of all people, her mother would be the most understanding.

"Don't yell, your brother is asleep in the next room." Sally warned. "What you said was not true, Estelle. Your brother is not looking to steal any of us away from you."

"Yeah? Well, each time he comes home, you treat him like-like a god! I'm left in the dust!" A few tears gathered on her long, thick lashes before she quickly blinked them away, as if to not seem weak.

"Estelle," Sally sighed, and Estelle looked up just in time to see her mother rubbing her temples. "What you need to realize is that we treat you both equally. However, when he's home, we do spend a little bit more time with him-" before Sally could finish, Estelle had jumped up in an angry triumph, interrupting her.

"So you admit it?"

"No, that's not all what she's saying." Her father frowned. "She's saying that we only spend more time with him when you're tucked away, asleep in bed. We see you all the time, Estelle. Rarely do we see Percy."

"You aren't even his father!" Estelle threw her head in her hands, her light pink nails digging into her scalp. Honestly, the nine-year-old began to wonder if out of everyone in this household, she was the smartest.

"You're right, Estelle, he's not." Her mother shot back. "He is, however, Percy's family, his stepfather, and that's certainly enough."

At the furious tone in her mother's normally calm, sweet voice, Estelle froze. Before she could make any sort of statement, however, her father butted in.

"But if you truly feel this way, 'Stelle, we can always have dinner and watch a little movie before bed if you'd like."

The offer was exciting, and a series of apologies spilled from her mouth as she realized what a child she had been to her parents.

"Nice to see that your apologies are after the offer." Paul laughed, ruffling her hair. Kissing the top of her head lightly, he mumbled a small apology for their sudden negligence.

"Before the movie, though, do you promise to not be so rude to your brother?" The soft voice of her mother entered her ears, and Estelle whipped her head up, a large grin on her face as she nodded rapidly. Sally returned her grin, and kissed the top of her hair, all of which causing Estelle's grin to grow larger.

 _I never said when,_ Estelle thought, her eyes growing sinister. _Get ready for tomorrow, big brother._


	2. Chapter 2

Coming up with a prank was not as easy as it was always made out to seem, Estelle quickly realized. Her original plan was to gather ideas and begin her planning at school, but that was quickly ruined when they performed many different activities during the day, something of which they never would have done had it not been her time to shine. To make matters worse, some boy in her grade, Ryan, had tripped and threw his large tray of food all over her white polo.

"I'm convinced the world is out to get me." Estelle grumbled as she continued wiping away at the large stain that had formed on her shirt. Her friends loud giggles had not helped once to tame her rage.

"Why? This is the only thing that's really gone wrong today." Her friend, Riley, spoke from beside her.

Estelle threw her head up in frustration and threw the napkin onto the table. Her pale, nimble fingers grasped at her brown hair, quickly tugging it into a ponytail before explaining.

"You don't understand!" She sighed, rubbing her eyes. "I was going to prank my brother, but I needed to plan it. I couldn't do it at home, so here was my best option, and now I can't even do it here!"

"My mom told me pranking others wasn't nice." Estelle's friend from across the table, Sarah, mumbled, playing with her fingers.

"Well, my brother isn't nice to me!" Estelle quickly defended. Resting her head in the palm of her hand, she shut her eyes. "My mom and dad won't let me prank him, so I can't do it at home. I know he's their favorite- they let him get away with everything."

"That's what my mom does with my little brother. He gets away with everything, and I'm the one that gets in trouble." Riley rolled her eyes, grumbling under her breath about how "unfair" it was.

"Maybe you should just scare him?" Sarah piped up, her green eyes shining with curiosity. "I mean, there isn't a lot of harm to come from it, and you can show him who is boss!"

Estelle's eyes widened, and a large grin overtook her face at the thought. Sarah was right, after all. She wouldn't get into any trouble for simply scaring him.

"You're a genius, Sarah!" Estelle exclaimed, jumping up in excitement. Before the three friends could exchange any other words on the subject, the bell rang, signaling for them to return to their class.

When the final bell of the day finally rung, and Estelle had returned home, a sense of nervousness filled her. Despite this anxious feeling, she was not going to back down.

"When do you think I should do it, Sparkles?" Estelle questioned her stuffed bear quietly. When there was no reply, Estelle flopped onto her back, analyzing the ceiling as she thought about the thousands of possibilities.

 _It's a Friday!_ She suddenly thought, sitting up. _I can stay up late and scare him once he falls asleep!_

A triumphant smile lit up her face as she stood, twiddling her thumbs as she excitedly awaited the moment to come.

When it finally did arrive, Estelle was exhausted. She could still faintly hear her mother and father speaking in the living room, but no longer could the nine-year-old wait, for she feared she would just fall asleep and forget everything about her dearest plan. She opened the door slowly, her heart pounding

against her chest as it creaked, but as soon as she realized her parents weren't paying attention, she darted across the hall, straight into the open room of her brother's.

"Oh no," Estelle whispered to herself as the cranks in her head turned. She hadn't even thought about what to do, or how to scare him in the first place. Suddenly, she was reminded of how her father told her to scare, or 'surprise', her mother on her birthday, and everything seemed to connect.

Inching slower and slower to his bed, Estelle snickered slightly as she prepared herself for the fun. Taking a deep breath, she crouched down and jumped onto his bed, a small, "boo!", escaping her lips. Though; the fun didn't last long when she was suddenly launched to the ground, Percy standing over her with a sword in his hand. His eyes darted across every part of the room and his breathing quickened before he brought the large sword down and pointed it straight at her throat.

"I've already escaped your hell, Tartarus! What more do you want from me?" Percy's eyes glowered as he spoke, his angry tone sending shivers down Estelle's spine.

In the back of her mind, Estelle realized that this situation was a wonderful way to get her brother out of her life for good; but the fear took over, and all she could do was let out a loud, bellowing scream, clenching her eyes shut tightly as she listened to her parents footsteps rush down the hall.

"Percy!" The loud voice of Estelle's father rang in her ears, and even when the pressure of her brother's hands left her small neck, Estelle still kept her eyes closed in fear.

Loud noises around the room caused her to shake, and the warm, gentle hands of her mother made her flinch, before she opened her eyes and the worried eyes of her mother made her cry. The sound of Estelle's sobbing cries echoed throughout the room, and the threatening stance Percy had towards her father suddenly shattered, and he fell to his knees, tugging onto his hair harshly.

"Estelle," she heard her mother whisper lightly in her ear. "Come on- let's go get you some water."

Pulling herself up, Estelle slowly walked the hall towards the living room where her mother quickly sat her down onto the couch. She rubbed her pale arms rapidly, shivers running up her spine at the small flashback to the moment that had just occurred. It was something that she never thought she would experience; especially at the ripe age of nine. Estelle genuinely believed her brother was going to _murder_ her- and this newfound belief only caused her hatred for the boy to grow.

"Estelle," the voice of her father cut Estelle out of her thoughts, and her head whipped up quickly, her eyes wide as she met the ones of her father. Next to him was Percy, and the panic that had once consumed her did that once more, but to her surprise, the same fear and panic was etched onto his tan face as well. "What you did was not right."

"But-" her small voice was cut off.

"No 'ands', 'ifs', or 'buts' about it, Estelle." Paul sighed, rubbing his face in an attempt to rid himself of the exhaustion and exasperation he currently faced. In a fluid motion, he waved his hands towards Percy, pointing at him to sit down. "Darling, there are just some things you don't understand. Too young to understand, even."

Estelle froze as her _attempted murderer_ took a seat next to her. Growing angry, She sprang up from her seat.

"I am not too young!" She exclaimed, her hair sticking to her forehead. "Maybe if you wouldn't keep secrets, this wouldn't have happened!"

"Sit down." Paul commanded, his daughter immediately obeying. "If you want an explanation so badly, I will give it to you, but I don't expect any questions should you not understand." He paused. "Alright?"

Estelle quickly nodded, casting a small glance towards the tired, slumped over form of her brother before grasping the glass of water her mother held in front of her.

"Right." Paul ran his fingers through his pepper-black hair. "Your brother has gone through many things, many of which are very gruesome."

Estelle opened her mouth, the question of, "what does 'gruesome' mean?" forming on her tongue, before her father shook his head, and she was left with her mouth slightly agape, a small reminder of a fish, ironically.

"Percy is a demigod, Estelle." Her mother suddenly spoke up, taking a seat in the recliner next to Paul, her arms crossed over her legs with her nimble fingers grasping her knees. "Don't you remember the trip you took to the 'Metropolitan Museum of Art'?" At Estelle's nod, Sally continued. "The things you learned about the Greek Gods- that is real."

"Huh?"

"Yes." Sally nodded, letting out a small giggle at the shock etched onto her daughter's face. "They are real, and-"

"And Percy is one?" Estelle cut her mom off, shaking with excitement and the thought of her brother being some sort of mythological god.

"No, no." Sally waved her hands as if to clear the air of the rumor, all the while Paul shot Estelle a look as if to say, " _settle down_ ". "No, Percy is the _son_ of a god. His father is Poseidon."

Leaning back onto the couch, Estelle looked unamused as she began to speak,

"I don't understand how this is similar to him- to him hurting me!"

"Your brother has been through a lot, Estelle." Paul said. "Quests, battles, everything a child shouldn't have to go through." He gave a small pause, debating on if he should say the last part. "He's been, quite literally, through hell."

"Well, yes." Sally looked shaken up for a moment. "His reaction to your silly antics was because of the things he has gone through."

"Are you saying he's murdered someone before, cause it really seemed like he was going to murder me?" Estelle asked curiously, her mind fluctuating with the terrifying thought of her brother being a wanted cereal- as she called it- killer.

"He wasn't going to murder you!" Sally reassured her, laughing awkwardly. "Your brother has something called PSTD-"

"Oh!" Estelle cried out, a small pang of guilt hitting her as she saw Percy jump in the corner of her eye. "I know what that is! We were talking about it in school. It means that you-you," Estelle stumbled over her words, struggling to describe the definition.

"It means that someone has difficulty recovering after experiencing or witnessing a terrifying event." Paul finished, and for the first time that night, giving a small smile at her attempt, the smile growing larger at her excited nod.

"Yeah! And you have things called," Estelle put on a thinking face. "Panic attacks and stuff." Her excitement over her knowledge soon disappeared as she came to the realization of her actions, guilt erupting inside of her and she looked over at her brother, noticing the fear still lurking on his face.

"It looks like she came to an understanding on her own." Estelle heard her mother whisper from across the room.

"Percy." Estelle spoke softly, her bottom lip quivering. When he looked up, his normally bright eyes were now dark, and she burst into tears. "I'm-" Estelle hiccupped. "I'm sorry!"

Quickly, Percy's older brother instincts kicked in, and he sat up in a flash, wrapping her in his arms as she sobbed. Guilt corrupted his mind, just as it did hers, and the only things the two whispered were rapid apologies.

Pulling away from the hug, Estelle wiped her cheeks.

"I'm sorry." She mumbled one last time. "I shouldn't have been jealous."

Percy shrugged, a small, lopsided smile appearing onto his face. "I would have been, too." He gave a small chuckle, his mood lightening at the smile developing on Estelle's face. "Probably would have pranked you, too, if we are be honest." Percy ignored Paul's distant " _don't tell her that!_ ".

Laughing, Estelle clutched her stomach, once again wiping her tears, but they now consisted of happy ones, rather than the latter.

"Yeah!" She agreed, nodding. "I probably would have attacked you, too."

Percy feigned shock, sucking in a small gasp.

"Hey!" He exclaimed. "You definitely deserved it!"

"Nuh-uh!" Estelle shook her head, sticking her tongue out at Percy. "You deserved being scared!"

Suddenly, a dark wave passed over Percy's face and the smile soon transformed into a smirk.

"Did I?" He asked, and at Estelle's nod, Percy leaped up and began ticking her, small gasps and shrieks leaving her mouth.

Across the room, Paul and Sally looked on with amusement, laughter filling the room with the occasional breathless shriek of, "stop!".

"I think they are finally acting like siblings, hm?" Paul mumbled against Sally's skin, his head nuzzled into the crevice of her neck.

"No thanks to me." Sally spoke triumphantly, pride swelling in her heart at her two bundles of joy across the room.

"Hey!" Paul exclaimed, shooting out of her neck to give her a look of shock.

Before long, everyone was involved in a play fight, and when Estelle awoke, she relished in the fun she had experienced, her mind claiming it to be 'the most fun she had ever had', and little did she know that her brother thought the exact same thing.


End file.
